CS238191B1 - Technological lubricant for hot rolling - Google Patents

Abstract

The invention relates to a mixture of granular lubricant and graphite for hot metal forming. The ratio of granular lubricant to graphite has a significant influence on the lubricating properties. The granular lubricant melts under the influence of the forming temperature and forms a melt with significant lubricating effects together with graphite. The lubricant according to the invention is considerably more effective than the individual components of the lubricant and significantly affects the reduction of mandrel wear, the reduction of electrical energy consumption and the increase of rolling speed. The lubricant is composed of a mixture of 30 to 70 wt. % of granular lubricant and 70 to 30 wt. % of graphite, whereby the granular lubricant contains 20 to 25 wt. % of potassium chloride KC1, 15 to 20 wt. % of calcium sulfate CaSO2), 15 to 18 wt. % of calcium hydrogen phosphate CaHPO2), 30 to 31 wt. ammonium nitrate NHÁNO3, 0.1 to 0.5% by weight magnesium sulfate MgSon, 0.6 to 1.0% by weight sodium chloride NaCl, 0.6 to 1.0% by weight calcium silicate CaSiOz, 1.6 to 2.0% by weight calcium fluoride CaFs, 0.5 to 1.0% by weight ferric or aluminum phosphate ALPO4, 0.1 to 0.5% by weight magnesium hydrogen phosphate MgHPO4, 4.0 to 5»θ% by weight ammonium hydrogen phosphate NH4H2PO4, 0.1 to 0.5% by weight sodium nitrate NaNOj, 0.2 to 0.8% by weight bentonite and the rest up to 100% by weight water.

Description

BÁR JOSEF ing., FRÍDEK-MÍSTEK

Technological grease for hot rolling

The invention relates to a mixture of granulated grease and graphite for hot metal forming. The ratio of granulated grease to graphite has a significant influence on the lubricating properties. The granulated grease melts due to the forming temperature and forms, together with graphite, a melt with significant lubricating effects. The lubricant according to the invention is considerably more efficient than the individual components of the lubricant and significantly affects the reduction of the wear of the mandrels, the reduction of the power consumption and the increase in the rolling speed.

The lubricant consists of a mixture of 3θ to 70% by weight. granulated lubricant and 70 to 30 wt.% graphite, wherein the granulated lubricant comprises 20 to 25 wt. % potassium chloride KCl, 15 to 20 wt. % calcium sulfate (CaSO2), 15 to 18 wt. % of acidic calcium phosphate (CaHPO2), 30 to 31 wt. % ammonium nitrate NHANO3, 0.1 to 0.5 wt. % MgSO4, 0.6 to 1.0 wt. % NaCl, 0.6 to 1.0 wt. % calcium silicate CaSiO 2, 1.6 to 2.0 wt. % of calcium fluoride CaFs, 0.5 to 1.0 wt. % of phosphate of rye or aluminum ALPO4, 0.1 to 0.5 wt. % magnesium phosphate MgHPO 4, 4.0 to 5% w / w; 0.1 to 0.5 wt.% sodium nitrate NaNO 3; 0.2 to 0.8 wt. % bentonite and the remainder to 100 wt. water.

238 191 Int. Cl. ¹

OJ C 10 M 103/02

- 1 238 191

The present invention relates to a technological lubricant for hot rolling, for tube rolling.

The expanding production of tubes of high-carbon and low-alloy steels forces us to focus our attention on high-quality production. Technological lubricants play an important role here.

Chlor Chlorides, phosphates, borides, low melting glass, soft metals and liquid lubricants have been used as hot rolling lubricants. The use of liquid lubricants in rolling thin-walled tubes greatly decreases the rolling temperature, thereby reducing their lubricating effects. In-service tests have shown an increased rolling speed in the process lubricants used hitherto due to reduced friction between the mandrel and the inner surface of the tube, but the disadvantage of the relatively rapid wear of the mandrel remains.

The above drawback removes the process hot rolling grease according to the invention. 3e composed of a mixture of 30-70 wt. granulated grease and 70-30 wt. wherein the granulated lubricant comprises 20-25 wt. KCl, 15-20 wt. calcium sulfate CaSO ₄ , 15-18 wt. % CaHPO4, 30-31 wt. ammonium nitrate NH4NO4, 0.1-0.5 wt. MgSO4, 0.6-1.0 wt. NaCl, 0.6-1.0% wt. calcium silicate CaSiO4, 1.6-2.0 wt. calcium fluoride Cap2 / 0.5-1.0 wt. % ferric or aluminum phosphate · PO ^, 0.1-0.5% wt. % MgHPO4, 4.0-5.0 wt. % ammonium phosphate acid NH4H2PO4, 0.1-0.5 wt. sodium nitrate NaNO4, 0.2-0.8 wt. bentonite and the remainder to 100 wt. water.

The advantage of this solution is, compared to currently used lubricants, an increase in the rolling speed by 7-23% according to the type of existing lubricant, a reduction of the mandrel wear by 15-25% again according to the type of lubricant used and a reduction of electric energy consumption.

238 191

The lubricant is very well dosed, does not smoke, does not have to be removed from the pipe surface and does not cause additional corrosion.

The following are three examples of the use of the lubricant in the rolling of steel pipes with a diameter of 168 mm on a rolling mill with an automatic system in the composition of individual substances by weight}

Example 1% graphite and 50% granulated grease

Example 2% graphite and 70% granulated grease

Example 3% graphite and 30% granulated lubricant, wherein the granulated lubricant always contains a friction of 23.4% _t CaSO4.

16.8%, NH ₄ NO ₃ 30.8%, CaHPO ₄ 16.3% _t 4.1%, CaF ₂

1.8%, NaCl 0.8%, CaSiO4 0.8%, MgHPO ₄ 0.3%, bentonite 0.5%, RP0 ₄ 0.8%, NaNO-j 0.2%, MgSO ₄ 0.1% , the rest water to 100%.

Claims (1)

SUBJECT OF THE INVENTION 238 191 Technological grease for hot rolling, characterized in that it is composed of a mixture of 30 to 70 wt. granulated lubricant and 70 to 30 wt. % of graphite, wherein the granulated lubricant contains 20 to 25 wt. of potassium chloride KCl, 15 to 20 wt. CaSO4, 15 to 18 wt. % calcium phosphate CaHPO ₄ , 30 to 31 wt. % ammonium nitrate NH4NO4, 0.1 to 0.5 wt. MgSO4, 0.6 to 1.0 wt. sodium chloride NaCl, 0.6 to 1.0 wt. calcium silicate CaSiO-i, 1.6 to 2.0 wt. calcium fluoride CaF ₂ , 0.5 to 1.0 wt. FeP0 FePO _4, or alumina-AlPO, 0.1 to 0.5 wt%. % MgHPO 4, 4.0 to 5.0 wt. acidic ammonium phosphate NH ₄ H ₂ P0 _4, 0, l to 0.5 wt%. sodium nitrate NaNO4, 0.2 to 0.8 wt. bentonite and the remainder to 100 wt. water.